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Topic: F9 Block 5 Updates and Discussion (Read 323620 times)

SpaceX has already explored the flight envelope pretty thoroughly with Block 3/4. They won't be asking Block 5 to fly much hotter reentries than the GTO missions they've already landed (because FH). They have a decent sample of post-GTO landed boosters to evaluate in order to set requirements for Block 5. I'd be surprised if they underperform on Block 5 reusability. Customer acceptance is a somewhat different story, but because of how surprisingly well Block 3/4 performed on those marginal GTO landings, SpaceX really has no excuses for failing to deliver a workhorse Block 5.

You're confusing "plan" with "reality". Plan is for block 5 to be the final revision. But no one (not even SpaceX) knows if that will be "reality" yet. Wait and see. Perhaps the first block 5 will live up to expectations in every possible way.

Yes, reality is yet to come. By plan I mean the design and its implementation.

The plan is for Block 5 to be the end product, not the start of another set of reuse hardware iterations -- that part of the development is just finishing. SpaceX will look hard at returned boosters for sure, and may (likely will) find weak-link components that need to be upgraded before or during major refurbishments in order to fly several ten-launch cycles.

I don't for a minute believe that the first Block 5s will live up to every expectation. I do believe that the basic design has been found to be satisfactory for large numbers of reuses -- what tweaks are needed as those flights are accumulated will be small potatoes relative to the basic design, IMO.

Hey, I heard block 5 is getting new legs. Does this mean something radical or will they look the same but be quicker to fold back? Also how could ship operations change, still crane onto the shore stand or could it go straight onto the truck?

The rumor seems to be that the new legs will allow them to be folded up after landing instead of removed, and that this will speed up recovery efforts. But details past that are AFIAK unknown. We'll be watching the first Block 5 recovery carefully!

When will the first block 5 fly? Also, is the first block 5 Falcon Heavy being built, yet?

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Chris Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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SpaceX has already explored the flight envelope pretty thoroughly with Block 3/4. They won't be asking Block 5 to fly much hotter reentries than the GTO missions they've already landed (because FH). They have a decent sample of post-GTO landed boosters to evaluate in order to set requirements for Block 5. I'd be surprised if they underperform on Block 5 reusability. Customer acceptance is a somewhat different story, but because of how surprisingly well Block 3/4 performed on those marginal GTO landings, SpaceX really has no excuses for failing to deliver a workhorse Block 5.

Hotter ?I think Block 5 re-entries will be cooler.Re-entry burn starts a few seconds sooner plus the higher thrust, so peak heating is lower, even if re-entry starts a bit faster.Most extra performance is used on the way up, but certainly some is saved for re-entry.The upper stage also has more performance too. All of that goes to the payload orbit.The whole point of Block 5 is no more re-entries too hot to reuse.

So Musk said the STP FH mission will be all Block 5, but they haven't announced the first F9 mission unless I missed it. That's what I'm most excited for now. To see what a rocket looks like that is built rugged, with expensive materials because they know they can amoritize the cost. Musk made it very clear how expensive the titanium grid fins are, how it's only reliable reuse that makes their use economical. I want that first reflight, then the 2nd, 3rd, 4th... and to find out how many boosters they really need.

So Musk said the STP FH mission will be all Block 5, but they haven't announced the first F9 mission unless I missed it. That's what I'm most excited for now. To see what a rocket looks like that is built rugged, with expensive materials because they know they can amoritize the cost. Musk made it very clear how expensive the titanium grid fins are, how it's only reliable reuse that makes their use economical. I want that first reflight, then the 2nd, 3rd, 4th... and to find out how many boosters they really need.

How many boosters they need will largely depend on how fast they can turn them around. The faster they can turn them around the less they need.

I'm sure they'll start out slow and cautiously to start with the Block 5's.

I want that first reflight, then the 2nd, 3rd, 4th... and to find out how many boosters they really need.

I wonder if they take the "self-insurance" opportunity with Starlink payloads to just run up gaudy numbers of same-core reuses and turnaround times to get real empircal results on the books to prove what they have.

I want that first reflight, then the 2nd, 3rd, 4th... and to find out how many boosters they really need.

I wonder if they take the "self-insurance" opportunity with Starlink payloads to just run up gaudy numbers of same-core reuses and turnaround times to get real empircal results on the books to prove what they have.

They aren't going to risk payloads.

Through inspections and evaluations they'll be able to determine if there is reasonable safety to fly the next mission.

SpaceX has already explored the flight envelope pretty thoroughly with Block 3/4. They won't be asking Block 5 to fly much hotter reentries than the GTO missions they've already landed (because FH). They have a decent sample of post-GTO landed boosters to evaluate in order to set requirements for Block 5. I'd be surprised if they underperform on Block 5 reusability. Customer acceptance is a somewhat different story, but because of how surprisingly well Block 3/4 performed on those marginal GTO landings, SpaceX really has no excuses for failing to deliver a workhorse Block 5.

Hotter ?I think Block 5 re-entries will be cooler.Re-entry burn starts a few seconds sooner plus the higher thrust, so peak heating is lower, even if re-entry starts a bit faster.AMost extra performance is used on the way up, but certainly some is saved for re-entry.The upper stage also has more performance too. All of that goes to the payload orbit.The whole point of Block 5 is no more re-entries too hot to reuse.

I think you have understood wrongly where the extra performance comes from.

The engine thrust increase won't give big extra performance because the amount of fuel is not increasing, it only gives slight decrease in gravity losses.

AFAIK considerable part of the "increased performance" of block 5 comes comes from less fuel used for re-entry and landing.

I want that first reflight, then the 2nd, 3rd, 4th... and to find out how many boosters they really need.

I wonder if they take the "self-insurance" opportunity with Starlink payloads to just run up gaudy numbers of same-core reuses and turnaround times to get real empircal results on the books to prove what they have.

Would be fun, but unfortunate certainty other customers and FAA would object to flights following the explosion, and not be willing to simply assume it was due to reuse.

SpaceX has already explored the flight envelope pretty thoroughly with Block 3/4. They won't be asking Block 5 to fly much hotter reentries than the GTO missions they've already landed (because FH). They have a decent sample of post-GTO landed boosters to evaluate in order to set requirements for Block 5. I'd be surprised if they underperform on Block 5 reusability. Customer acceptance is a somewhat different story, but because of how surprisingly well Block 3/4 performed on those marginal GTO landings, SpaceX really has no excuses for failing to deliver a workhorse Block 5.

Hotter ?I think Block 5 re-entries will be cooler.Re-entry burn starts a few seconds sooner plus the higher thrust, so peak heating is lower, even if re-entry starts a bit faster.AMost extra performance is used on the way up, but certainly some is saved for re-entry.The upper stage also has more performance too. All of that goes to the payload orbit.The whole point of Block 5 is no more re-entries too hot to reuse.

I think you have understood wrongly where the extra performance comes from.

The engine thrust increase won't give big extra performance because the amount of fuel is not increasing, it only gives slight decrease in gravity losses.

AFAIK considerable part of the "increased performance" of block 5 comes comes from less fuel used for re-entry and landing.

Amount of fuel loaded depends on LOX and helium load times among other factors, we don't know that it won't be higher than Block 3&4.

SpaceX has already explored the flight envelope pretty thoroughly with Block 3/4. They won't be asking Block 5 to fly much hotter reentries than the GTO missions they've already landed (because FH). They have a decent sample of post-GTO landed boosters to evaluate in order to set requirements for Block 5. I'd be surprised if they underperform on Block 5 reusability. Customer acceptance is a somewhat different story, but because of how surprisingly well Block 3/4 performed on those marginal GTO landings, SpaceX really has no excuses for failing to deliver a workhorse Block 5.

Hotter ?I think Block 5 re-entries will be cooler.Re-entry burn starts a few seconds sooner plus the higher thrust, so peak heating is lower, even if re-entry starts a bit faster.AMost extra performance is used on the way up, but certainly some is saved for re-entry.The upper stage also has more performance too. All of that goes to the payload orbit.The whole point of Block 5 is no more re-entries too hot to reuse.

I think you have understood wrongly where the extra performance comes from.

The engine thrust increase won't give big extra performance because the amount of fuel is not increasing, it only gives slight decrease in gravity losses.

AFAIK considerable part of the "increased performance" of block 5 comes comes from less fuel used for re-entry and landing.

Amount of fuel loaded depends on LOX and helium load times among other factors, we don't know that it won't be higher than Block 3&4.

The advantage of 5-10 min. shorter load time is pretty marginal. It's not nothing and every bit helps, but still. If the Block 5 is going to deliver big improvements in performance, I can't see that as being a real significant part of the reason why.